In order to store and transport seasonings, beverages, alcoholic liquors and the like, resin containers are frequently used. A large capacity container has a large body diameter, so that it is difficult to grip the container with one hand. For this reason, in some cases, a body part of the container is formed with a grip part during blow molding.
Patent Document 1 discloses a mold for blow molding, in which one end of a link member is provided with a protrusion for forming a grip part and another end of the link member is provided with a drive mechanism for rotating the link member with a shaft part being interposed therebetween.